A decoloring device performs decolorization processing by sequentially taking in a sheet on which an image is formed using a coloring agent which is decolored by heating at a predetermined temperature, and pressurizing and heating the sheet at a temperature of, for example, 180° C. to 200° C.
In the decoloring device, a scanner is provided to read a manuscript before the decolorization processing or to confirm a decolorized state after the decolorization processing. It is desirable to decrease a size of a decoloring device to use the decoloring device as part of an automatic document feeding (ADF) device of an image forming apparatus such as an MFP and the like.
In addition, when decreasing a size of the decoloring device, an interval between a decoloring unit and a scanner becomes narrow. For this reason, when a length of a sheet in a longitudinal direction is longer than the interval between the decoloring unit and the scanner (when the sheet spans across the scanner and the decoloring unit), a tip portion of the sheet reaches an inlet of the decoloring unit during read processing by the scanner. That is, it is possible to start the decolorization processing earlier than before.
However, when a sheet taken into the decoloring unit during the read processing by the scanner is jammed, the sheet stays at the decoloring unit in a high temperature state, and the sheet is decolorized before reading is completed. Therefore, it is not possible to save image data of a sheet before decolorization by re-feeding the sheet from a sheet feeding unit and performing the read processing again.